Thermally conductive aluminum alloy and application thereof

ABSTRACT

The present disclosure discloses a heat-conductive aluminum alloy and application thereof. The heat-conductive aluminum alloy contains alloying elements, unavoidable impurities and the balance of an aluminum element. Based on the total weight of the heat-conductive aluminum alloy, the alloying elements include: 5.0 to 11.0% by weight of Si, 0.4 to 1.0% by weight of Fe, 0.2 to 1.0% by weight of Mg, less than 0.1% by weight of Zn, less than 0.1% by weight of Mn, less than 0.1% by weight of Sr and less than 0.1% by weight of Cu. The heat-conductive aluminum alloy prepared by the present disclosure has a tensile strength of not less than 250 MPa, a yield strength of not less than 150 MPa, an elongation of not less than 3.5%, and a thermal conductivity of not less than 150 W/(m·K).

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure claims priority to Chinese Patent Application No. 201611038514.1 filed in China on Nov. 23, 2016. The entire content of the above-referenced application is incorporated herein by reference.

FIELD

The present disclosure relates to the technical field of aluminum alloy, and in particular to a thermally conductive aluminum alloy and application thereof.

BACKGROUND

Aluminum alloy materials are widely used in aviation, aerospace, electronic and electrical products, automotive, machinery manufacturing and other fields because of their characteristics of low density, high strength, good plasticity, excellent electrical conductivity, thermal conductivity and corrosion resistance.

Since electronic and electrical products tend to be miniaturized in recent years, the conventional aluminum alloy materials such as ADC12 on the market have a thermal conductivity of only 96 W/(m·K), which has been difficult to meet the demand for high strength and high thermal conductivity of electronic and electrical products. There is an urgent need to develop a new aluminum alloy material that has high thermal conductivity while having the advantages of high mechanical properties and low cost.

SUMMARY

An object of the present disclosure is to provide a heat-conductive aluminum alloy. The heat-conductive aluminum alloy has a high thermal conductivity and can be recycled.

In order to achieve the above object, the present disclosure provides a heat-conductive aluminum alloy, containing alloying elements, unavoidable impurities and the balance of an aluminum element, where based on the total weight of the heat-conductive aluminum alloy, the alloying elements include: 5.0 to 11.0% by weight of Si, 0.4 to 1.0% by weight of Fe, 0.2 to 1.0% by weight of Mg, less than 0.1% by weight of Zn, less than 0.1% by weight of Mn, less than 0.1% by weight of Sr and less than 0.1% by weight of Cu.

Through the above technical solution, the heat-conductive aluminum alloy prepared by the present disclosure has a tensile strength of not less than 250 MPa, a yield strength of not less than 150 MPa, an elongation of not less than 3.5%, and a thermal conductivity of not less than 150 W/(m·K). The heat-conductive aluminum alloy has high mechanical properties and good flow forming property, and the forming fluidity measured by a mosquito coil mold is not less than 1150 mm. The heat-conductive aluminum alloy can be recycled and reused multiple times. The thermal conductivity of the die-casting material after 5 times of recycling is >125 W/(m·K), which is 83% or above of the thermal conductivity of the new material. The thermal conductivity of the die-casting material after 10 times of recycling is >112 W/(m·K), which is 75% or above of the thermal conductivity of the new material.

Optionally, based on the total weight of the heat-conductive aluminum alloy, the alloying elements include: 8.0 to 11.0% by weight of Si, 0.4 to 0.6% by weight of Fe, 0.4 to 0.8% by weight of Mg, less than 0.01% by weight of Zn, less than 0.01% by weight of Mn, less than 0.1% by weight of Sr and less than 0.01% by weight of Cu. The heat-conductive aluminum alloy prepared according to the formula has a tensile strength of not less than 270 MPa, a yield strength of not less than 160 MPa, an elongation of not less than 5%, and a thermal conductivity of not less than 160 W/(m·K).

Optionally, the impurity elements in the heat-conductive aluminum alloy do not exceed 0.2% by weight.

Optionally, the heat-conductive aluminum alloy consists of 5.0 to 11.0% by weight of Si, 0.4 to 1.0% by weight of Fe, 0.2 to 1.0% by weight of Mg, less than 0.1% by weight of Zn, less than 0.1% by weight of Mn, less than 0.1% by weight of Sr, less than 0.1% by weight of Cu, not more than 0.2% by weight of impurity elements and the balance of aluminum.

Optionally, the heat-conductive aluminum alloy consists of 8.0 to 11.0% by weight of Si, 0.4 to 0.6% by weight of Fe, 0.4 to 0.8% by weight of Mg, less than 0.01% by weight of Zn, less than 0.01% by weight of Mn, less than 0.1% by weight of Sr, less than 0.01% by weight of Cu, not more than 0.2% by weight of impurity elements and the balance of aluminum.

The present disclosure further provides applications of the heat-conductive aluminum alloy as described above in the manufacture of metal structural members and/or heat sinks for electronic and electrical products.

Other features and advantages of the present disclosure are described in detail in the Detailed Description part below.

DETAILED DESCRIPTION

Specific implementations of the present disclosure are described in detail below. It should be understood that the specific implementations described herein are merely used to describe and explain the present disclosure rather than limit the present disclosure.

Herein, without any indication to the contrary, the values of tensile strength, yield strength and elongation of a heat-conductive aluminum alloy refer to the tensile strength, yield strength and elongation of a metallic material tested in accordance with GB/T 228.1-2010 Metallic Materials-Tensile Testing-Part 1: Method of test at room temperature.

A first aspect of the present disclosure provides a heat-conductive aluminum alloy, containing alloying elements, unavoidable impurities and the balance of an aluminum element, where based on the total weight of the heat-conductive aluminum alloy, the alloying elements may include: 5.0 to 11.0% by weight of Si, 0.4 to 1.0% by weight of Fe, 0.2 to 1.0% by weight of Mg, less than 0.1% by weight of Zn, less than 0.1% by weight of Mn, less than 0.1% by weight of Sr and less than 0.1% by weight of Cu.

Through the above technical solution, the heat-conductive aluminum alloy prepared by the present disclosure has a tensile strength of not less than 250 MPa, a yield strength of not less than 150 MPa, an elongation of not less than 3.5%, and a thermal conductivity of not less than 150 W/(m·K). The heat-conductive aluminum alloy has high mechanical properties and good flow forming property, and the forming fluidity measured by a mosquito coil mold is not less than 1150 mm. The heat-conductive aluminum alloy can be recycled and reused multiple times. The thermal conductivity of the die-casting material after 5 times of recycling is not less than 125 W/(m·K), which is 83% or above of the thermal conductivity of the new material. The thermal conductivity of the die-casting material after 10 times of recycling is not less than 112 W/(m·K), which is 75% or above of the thermal conductivity of the new material.

According to the first aspect of the present disclosure, in order to further improve the mechanical properties, thermal conductivity and casting properties of the heat-conductive aluminum alloy, based on the total weight of the heat-conductive aluminum alloy, the alloying elements may include: 8.0 to 11.0% by weight of Si, 0.4 to 0.6% by weight of Fe, 0.4 to 0.8% by weight of Mg, less than 0.01% by weight of Zn, less than 0.01% by weight of Mn, less than 0.1% by weight of Sr and less than 0.01% by weight of Cu. The heat-conductive aluminum alloy prepared according to the formula has a tensile strength of not less than 270 MPa, a yield strength of not less than 160 MPa, an elongation of not less than 5%, and a thermal conductivity of not less than 160 W/(m·K). The thermal conductivity of the die-casting material after 5 times of recycling is not less than 138 W/(m·K), which is 86% or above of the thermal conductivity of the new material. The thermal conductivity of the die-casting material after 10 times of recycling is not less than 125 W/(m·K), which is 78% or above of the thermal conductivity of the new material.

According to the first aspect of the present disclosure, the purity of the aluminum alloy is one of the important factors affecting the properties of the aluminum alloy. In order to make the heat-conductive aluminum alloy of the present disclosure excellent in properties, the impurity elements in the heat-conductive aluminum alloy do not exceed 0.2 wt %.

According to the first aspect of the present disclosure, in order to further improve the mechanical properties, thermal conductivity and casting properties of the heat-conductive aluminum alloy, the heat-conductive aluminum alloy consists of 5.0 to 11.0% by weight of Si, 0.4 to 1.0% by weight of Fe, 0.2 to 1.0% by weight of Mg, less than 0.1% by weight of Zn, less than 0.1% by weight of Mn, less than 0.1% by weight of Sr, less than 0.1% by weight of Cu, not more than 0.2% by weight of impurity elements and the balance of aluminum. The heat-conductive aluminum alloy prepared according to the formula has a tensile strength of not less than 250 MPa, a yield strength of not less than 150 MPa, an elongation of not less than 3.5%, and a thermal conductivity of not less than 150 W/(m·K). The heat-conductive aluminum alloy has good flow forming property, and the forming fluidity measured by a mosquito coil mold is not less than 1150 mm.

According to the first aspect of the present disclosure, in order to further improve the mechanical properties, thermal conductivity and casting properties of the heat-conductive aluminum alloy, the heat-conductive aluminum alloy consists of 8.0 to 11.0% by weight of Si, 0.4 to 0.6% by weight of Fe, 0.4 to 0.8% by weight of Mg, less than 0.01% by weight of Zn, less than 0.01% by weight of Mn, less than 0.1% by weight of Sr and less than 0.01% by weight of Cu. The heat-conductive aluminum alloy prepared according to the formula has a tensile strength of not less than 270 MPa, a yield strength of not less than 160 MPa, an elongation of not less than 5%, and a thermal conductivity of not less than 160 W/(m·K). The thermal conductivity of the die-casting material after 5 times of recycling is not less than 138 W/(m·K), which is 86% or above of the thermal conductivity of the new material. The thermal conductivity of the die-casting material after 10 times of recycling is not less than 125 W/(m·K), which is 78% or above of the thermal conductivity of the new material.

A second aspect of the present disclosure provides application of the heat-conductive aluminum alloy as described above in the manufacture of metal structural members and/or heat sinks for electronic and electrical products.

The present invention will be further illustrated by the following embodiments, but the present invention is not limited thereby.

Embodiment 1

In this embodiment, based on the total weight of the heat-conductive aluminum alloy as 100 parts by weight, the heat-conductive aluminum alloy contains 5.0 parts by weight of Si, 1.0 part by weight of Fe, 0.2 part by weight of Mg, 0.05 part by weight of Zn, 0.05 part by weight of Mn, 0.05 part by weight of Sr, 0.05 part by weight of Cu and the balance of Al.

First, the furnace was preheated at 400° C. for 25 minutes and purged with argon gas, the corresponding parts by weight of pure aluminum ingot was added for melting, and when the temperature of the pure aluminum liquid reached 800° C., the pure aluminum liquid was allowed to stand for 25 minutes to fully melt the pure aluminum ingot. The furnace was cooled to 760° C., 5.0 parts by weight of pure silicon was added, and the mixture was allowed to stand at a constant temperature for 25 minutes, and after melting, stirring was continued for 15 minutes. When the furnace was cooled to 700° C., the remaining intermediate alloy was added, and after melting was completed, the mixture was allowed to stand. Finally, 0.2 part by weight of magnesium was finally added, after melting was completed, stirring was continued for 8 minutes, the dross was removed, a refining agent was added at 700° C. for refining, and the mixture was stirred for 15 minutes. Then, the ladle composition analysis was carried out to inspect the component content of the alloy, and the melt which is unqualified in the component content was subjected to feeding or dilution for reaching standards, so as to obtain the heat-conductive aluminum alloy of this embodiment.

Embodiment 2

In this embodiment, based on the total weight of the heat-conductive aluminum alloy as 100 parts by weight, the heat-conductive aluminum alloy contains 11.0 parts by weight of Si, 0.4 part by weight of Fe, 1.0 part by weight of Mg, 0.05 part by weight of Zn, 0.05 part by weight of Mn, 0.05 part by weight of Sr, 0.05 part by weight of Cu and the balance of Al.

First, the furnace was preheated at 400° C. for 25 minutes and purged with argon gas, the corresponding parts by weight of pure aluminum ingot was added for melting, and when the temperature of the pure aluminum liquid reached 800° C., the pure aluminum liquid was allowed to stand for 25 minutes to fully melt the pure aluminum ingot. The furnace was cooled to 760° C., 11.0 parts by weight of pure silicon was added, and the mixture was allowed to stand at a constant temperature for 25 minutes, and after melting, stirring was continued for 15 minutes. When the furnace was cooled to 700° C., the remaining intermediate alloy was added, and after melting was completed, the mixture was allowed to stand. Finally, 1.0 part by weight of magnesium was added, after melting was completed, stirring was continued for 8 minutes, the dross was removed, a refining agent was added at 700° C. for refining, and the mixture was stirred for 15 minutes. Then, the ladle composition analysis was carried out to inspect the component content of the alloy, and the melt which is unqualified in the component content was subjected to feeding or dilution for reaching standards, so as to obtain the heat-conductive aluminum alloy of this embodiment.

Embodiment 3

In this embodiment, based on the total weight of the heat-conductive aluminum alloy as 100 parts by weight, the heat-conductive aluminum alloy contains 8.0 parts by weight of Si, 0.4 part by weight of Fe, 0.4 part by weight of Mg, 0.008 part by weight of Zn, 0.008 part by weight of Mn, 0.05 part by weight of Sr, 0.008 part by weight of Cu and the balance of Al.

First, the furnace was preheated at 400° C. for 25 minutes and purged with argon gas, the corresponding parts by weight of pure aluminum ingot was added for melting, and when the temperature of the pure aluminum liquid reached 800° C., the pure aluminum liquid was allowed to stand for 25 minutes to fully melt the pure aluminum ingot. The furnace was cooled to 760° C., 8.0 parts by weight of pure silicon was added, and the mixture was allowed to stand at a constant temperature for 25 minutes, and after melting, stirring was continued for 15 minutes. When the furnace was cooled to 700° C., the remaining intermediate alloy was added, and after melting was completed, the mixture was allowed to stand. Finally, 0.4 part by weight of magnesium was added, after melting was completed, stirring was continued for 8 minutes, the dross was removed, a refining agent was added at 700° C. for refining, and the mixture was stirred for 15 minutes. Then, the ladle composition analysis was carried out to inspect the component content of the alloy, and the melt which is unqualified in the component content was subjected to feeding or dilution for reaching standards, so as to obtain the heat-conductive aluminum alloy of this embodiment.

Embodiment 4

In this embodiment, based on the total weight of the heat-conductive aluminum alloy as 100 parts by weight, the heat-conductive aluminum alloy contains 11.0 parts by weight of Si, 0.6 part by weight of Fe, 0.8 part by weight of Mg, 0.002 part by weight of Zn, 0.002 part by weight of Mn, 0.002 part by weight of Sr, 0.002 part by weight of Cu and the balance of Al.

First, the furnace was preheated at 400° C. for 25 minutes and purged with argon gas, the corresponding parts by weight of pure aluminum ingot was added for melting, and when the temperature of the pure aluminum liquid reached 800° C., the pure aluminum liquid was allowed to stand for 25 minutes to fully melt the pure aluminum ingot. The furnace was cooled to 760° C., 11.0 parts by weight of pure silicon was added, and the mixture was allowed to stand at a constant temperature for 25 minutes, and after melting, stirring was continued for 15 minutes. When the furnace was cooled to 700° C., the remaining intermediate alloy was added, and after melting was completed, the mixture was allowed to stand. Finally, 0.8 part by weight of magnesium was added, after melting was completed, stirring was continued for 8 minutes, the dross was removed, a refining agent was added at 700° C. for refining, and the mixture was stirred for 15 minutes. Then, the ladle composition analysis was carried out to inspect the component content of the alloy, and the melt which is unqualified in the component content was subjected to feeding or dilution for reaching standards, so as to obtain the heat-conductive aluminum alloy of this embodiment.

Embodiment 5

In this embodiment, based on the total weight of the heat-conductive aluminum alloy as 100 parts by weight, the heat-conductive aluminum alloy contains 9.5 parts by weight of Si, 0.6 part by weight of Fe, 0.6 part by weight of Mg, 0.005 part by weight of Zn, 0.005 part by weight of Mn, 0.05 part by weight of Sr, 0.005 part by weight of Cu and the balance of Al.

First, the furnace was preheated at 400° C. for 25 minutes and purged with argon gas, the corresponding parts by weight of pure aluminum ingot was added for melting, and when the temperature of the pure aluminum liquid reached 800° C., the pure aluminum liquid was allowed to stand for 25 minutes to fully melt the pure aluminum ingot. The furnace was cooled to 760° C., 9.5 parts by weight of pure silicon was added, and the mixture was allowed to stand at a constant temperature for 25 minutes, and after melting, stirring was continued for 15 minutes. When the furnace was cooled to 700° C., the remaining intermediate alloy was added, and after melting was completed, the mixture was allowed to stand. Finally, 0.6 part by weight of magnesium was added, after melting was completed, stirring was continued for 8 minutes, the dross was removed, a refining agent was added at 700° C. for refining, and the mixture was stirred for 15 minutes. Then, the ladle composition analysis was carried out to inspect the component content of the alloy, and the melt which is unqualified in the component content was subjected to feeding or dilution for reaching standards, so as to obtain the heat-conductive aluminum alloy of this embodiment.

Comparative Example 1

In this comparative example, based on the total weight of the heat-conductive aluminum alloy as 100 parts by weight, the heat-conductive aluminum alloy contains 4.2 parts by weight of Si, 0.2 part by weight of Fe, 0.4 part by weight of Mg, 0.05 part by weight of Zn, 0.05 part by weight of Mn, 0.05 part by weight of Ni, 0.05 part by weight of Cr and the balance of Al.

First, the furnace was preheated at 400° C. for 25 minutes and purged with argon gas, the corresponding parts by weight of pure aluminum ingot was added for melting, and when the temperature of the pure aluminum liquid reached 800° C., the pure aluminum liquid was allowed to stand for 25 minutes to fully melt the pure aluminum ingot. The furnace was cooled to 760° C., 4.2 parts by weight of pure silicon was added, and the mixture was allowed to stand at a constant temperature for 25 minutes, and after melting, stirring was continued for 15 minutes. When the furnace was cooled to 700° C., the remaining intermediate alloy was added, and after melting was completed, the mixture was allowed to stand. Finally, 0.4 part by weight of magnesium was added, after melting was completed, stirring was continued for 8 minutes, the dross was removed, a refining agent was added at 700° C. for refining, and the mixture was stirred for 15 minutes. Then, the ladle composition analysis was carried out to inspect the component content of the alloy, and the melt which is unqualified in the component content was subjected to feeding or dilution for reaching standards, so as to obtain the heat-conductive aluminum alloy of this embodiment.

Comparative Example 2

In this comparative example, based on the total weight of the heat-conductive aluminum alloy as 100 parts by weight, the heat-conductive aluminum alloy contains 4.0 parts by weight of Si, 0.2 part by weight of Fe, 0.1 part by weight of Mg, 0.15 part by weight of Zn, 0.15 part by weight of Mn, 0.15 part by weight of Sr, 0.15 part by weight of Cu and the balance of Al.

First, the furnace was preheated at 400° C. for 25 minutes and purged with argon gas, the corresponding parts by weight of pure aluminum ingot was added for melting, and when the temperature of the pure aluminum liquid reached 800° C., the pure aluminum liquid was allowed to stand for 25 minutes to fully melt the pure aluminum ingot. The furnace was cooled to 760° C., 4.0 parts by weight of pure silicon was added, and the mixture was allowed to stand at a constant temperature for 25 minutes, and after melting, stirring was continued for 15 minutes. When the furnace was cooled to 700° C., the remaining intermediate alloy was added, and after melting was completed, the mixture was allowed to stand. Finally, 0.1 part by weight of magnesium was added, after melting was completed, stirring was continued for 8 minutes, the dross was removed, a refining agent was added at 700° C. for refining, and the mixture was stirred for 15 minutes. Then, the ladle composition analysis was carried out to inspect the component content of the alloy, and the melt which is unqualified in the component content was subjected to feeding or dilution for reaching standards, so as to obtain the heat-conductive aluminum alloy of this embodiment.

Comparative Example 3

In this comparative example, based on the total weight of the heat-conductive aluminum alloy as 100 parts by weight, the heat-conductive aluminum alloy contains 12.0 parts by weight of Si, 0.2 part by weight of Fe, 0.1 part by weight of Mg, 0.15 part by weight of Zn, 0.15 part by weight of Mn, 0.15 part by weight of Sr, 0.15 part by weight of Cu and the balance of Al.

First, the furnace was preheated at 400° C. for 25 minutes and purged with argon gas, the corresponding parts by weight of pure aluminum ingot was added for melting, and when the temperature of the pure aluminum liquid reached 800° C., the pure aluminum liquid was allowed to stand for 25 minutes to fully melt the pure aluminum ingot. The furnace was cooled to 760° C., 12.0 parts by weight of pure silicon was added, and the mixture was allowed to stand at a constant temperature for 25 minutes, and after melting, stirring was continued for 15 minutes. When the furnace was cooled to 700° C., the remaining intermediate alloy was added, and after melting was completed, the mixture was allowed to stand. Finally, 0.1 part by weight of magnesium was added, after melting was completed, stirring was continued for 8 minutes, the dross was removed, a refining agent was added at 700° C. for refining, and the mixture was stirred for 15 minutes. Then, the ladle composition analysis was carried out to inspect the component content of the alloy, and the melt which is unqualified in the component content was subjected to feeding or dilution for reaching standards, so as to obtain the heat-conductive aluminum alloy of this embodiment.

Comparative Example 4

In this comparative example, based on the total weight of the heat-conductive aluminum alloy as 100 parts by weight, the heat-conductive aluminum alloy contains 4.0 parts by weight of Si, 1.2 parts by weight of Fe, 1.0 part by weight of Mg, 0.15 part by weight of Zn, 0.15 part by weight of Mn, 0.15 part by weight of Sr, 0.15 part by weight of Cu and the balance of Al.

First, the furnace was preheated at 400° C. for 25 minutes and purged with argon gas, the corresponding parts by weight of pure aluminum ingot was added for melting, and when the temperature of the pure aluminum liquid reached 800° C., the pure aluminum liquid was allowed to stand for 25 minutes to fully melt the pure aluminum ingot. The furnace was cooled to 760° C., 4.0 parts by weight of pure silicon was added, and the mixture was allowed to stand at a constant temperature for 25 minutes, and after melting, stirring was continued for 15 minutes. When the furnace was cooled to 700° C., the remaining intermediate alloy was added, and after melting was completed, the mixture was allowed to stand. Finally, 1.0 part by weight of magnesium was added, after melting was completed, stirring was continued for 8 minutes, the dross was removed, a refining agent was added at 700° C. for refining, and the mixture was stirred for 15 minutes. Then, the ladle composition analysis was carried out to inspect the component content of the alloy, and the melt which is unqualified in the component content was subjected to feeding or dilution for reaching standards, so as to obtain the heat-conductive aluminum alloy of this embodiment.

Test Embodiment 1

This test embodiment is used to determine the mechanical properties, thermal conductivity and flow formability at room temperature of the heat-conductive aluminum alloys obtained in Embodiments 1 to 5 and Comparative Examples 1 to 4.

Determination of thermal conductivity: The heat-conductive aluminum alloy in each of the embodiments and comparative examples was prepared into a circular sample having a diameter of 12.7 mm and a thickness of 25.4 mm; a graphite coating was uniformly sprayed on both sides of the sample to be tested; and the treated sample was placed in a laser thermal conductivity tester for testing. The test was performed in accordance with ASTM E1461 Standard Test Method for Thermal Diffusivity by the Flash Method. The specific test results are shown in Table 1.

The tensile strength, yield strength and elongation of the aluminum alloy were tested in accordance with GB/T 228.1-2010 Metallic Materials-Tensile Testing-Part 1: Method of test at room temperature. The sheets extruded in Embodiments 1 to 5 and Comparative Examples 1 to 4 were subjected to wire-cutting to prepare standard tensile samples, and the axial direction of the tensile specimens was consistent with the extrusion direction. The specific test results are shown in Table 1.

The fluidity of the heat-conductive aluminum alloy material was determined by a mosquito coil mold: The mosquito coil mold was a mold having a mold cavity in a mosquito coil shape, and the formed metal member had a spiral shape. The heat-conductive aluminum alloys of Embodiments 1 to 5 and Comparative Examples 1 to 4 were smelted at 730° C., and after being completely melted, they were air-cooled to 690° C. and cast into a mosquito coil mold for a fluidity test. The length of the formed aluminum alloy spiral sample was measured. The specific results are shown in Table 1.

TABLE 1 Thermal Tensile Yield Elon- Forming Conductivity Strength Strength gation Fluidity Example (W/(m · K)) (MPa) (MPa) (%) (mm) Embodiment 1 150 260 151 3.5 1200 Embodiment 2 153 270 162 4.0 1150 Embodiment 3 164 270 169 5.5 1200 Embodiment 4 165 287 178 5.0 1220 Embodiment 5 169 275 172 6.0 1250 Comparative  93 220 159 2.6 1000 Example 1 Comparative 100 239 147 2.0  980 Example 2 Comparative 123 253 153 3.9 1050 Example 3 Comparative 130 268 150 2.8 1100 Example 4

It can be seen from the comparison of the results of Embodiments 1 to 5 and Comparative Examples 1 to 4 that the heat-conductive aluminum alloy prepared by the present disclosure has better mechanical properties: the tensile strength is not less than 250 MPa, the yield strength is not less than 150 MPa, and the elongation is not less than 3.5%. While having good mechanical properties, the heat-conductive aluminum alloy has good flow forming property, and the forming fluidity measured by a mosquito coil mold is not less than 1150 mm. The thermal conductivity is not less than 150 W/(m·K). In particular, when the heat-conductive aluminum alloy contains 8.0 to 11.0% by weight of Si, 0.4 to 0.6% by weight of Fe, 0.4 to 0.8% by weight of Mg, less than 0.01% by weight of Zn, less than 0.01% by weight of Mn, less than 0.1% by weight of Sr and less than 0.01% by weight of Cu, the prepared heat-conductive aluminum alloy has a tensile strength of not less than 270 MPa, a yield strength of not less than 160 MPa, an elongation of not less than 5% and a thermal conductivity of not less than 160 W/(m·K).

Test Embodiment 2

This test embodiment is used to determine the thermal conductivity of the heat-conductive aluminum alloys obtained in Embodiments 1 to 5 and Comparative Examples 1 to 4 after recycling.

Recycling of heat-conductive aluminum alloy: The new material heat-conductive aluminum alloy in each of the embodiments and comparative examples was separately collected and melted at 760° C. for 1 hour; the molten material was placed in a crucible and mechanically stirred at a rate of 1200 rpm for 30 min, and then cooled to obtain the recycled heat-conductive aluminum alloy; and the thermal conductivity of the aluminum alloy after 5 and 10 times of recycling was measured with reference to the thermal conductivity measurement method in Test Embodiment 1. The specific test results are shown in Table 2.

TABLE 2 Thermal Conductivity after Recycling n times (W/(m · K)) Example 5 times 10 times Embodiment 1 125 112 Embodiment 2 127 117 Embodiment 3 138 125 Embodiment 4 140 131 Embodiment 5 149 137 Comparative 78 69 Example 1 Comparative 84 77 Example 2 Comparative 98 90 Example 3 Comparative 107 99 Example 4

It can be seen from the comparison of the results of Embodiments 1 to 5 and Comparative Examples 1 to 4 that the heat-conductive aluminum alloy prepared by the present disclosure can be recycled and reused multiple times. The thermal conductivity of the die-casting material after 5 times of recycling is not less than 125 W/(m·K), which is 83% or above of the thermal conductivity of the new material. The thermal conductivity of the die-casting material after 10 times of recycling is not less than 112 W/(m·K), which is 75% or above of the thermal conductivity of the new material. In particular, when the heat-conductive aluminum alloy contains 8.0 to 11.0% by weight of Si, 0.4 to 0.6% by weight of Fe, 0.4 to 0.8% by weight of Mg, less than 0.01% by weight of Zn, less than 0.01% by weight of Mn, less than 0.1% by weight of Sr and less than 0.01% by weight of Cu, the thermal conductivity of the die-casting material after 5 times of recycling of the heat-conductive aluminum alloy is not less than 138 W/(m·K), which is 86% or above of the thermal conductivity of the new material. The thermal conductivity of the die-casting material after 10 times of recycling is not less than 125 W/(m·K), which is 78% or above of the thermal conductivity of the new material.

Although preferred implementations of the present disclosure are described in detail above, the present disclosure is not limited to specific details in the foregoing implementations. Various simple variations can be made to the technical solutions of the present disclosure within the scope of the technical idea of the present disclosure, and such simple variations all fall within the protection scope of the present disclosure.

It should be further noted that the specific technical features described in the foregoing specific implementations can be combined in any appropriate manner provided that no conflict occurs. To avoid unnecessary repetition, various possible combination manners are not further described in the present disclosure.

In addition, various different implementations of the present disclosure may alternatively be combined randomly. Such combinations should also be considered as the content disclosed in the present disclosure provided that these combinations do not depart from the concept of the present disclosure. 

1. A heat-conductive aluminum alloy, comprising: alloying elements; unavoidable impurities; and balance of an aluminum element, wherein, based on total weight of the heat-conductive aluminum alloy, the alloying elements comprise: 5.0 to 11.0% by weight of Si, 0.4 to 1.0% by weight of Fe, 0.2 to 1.0% by weight of Mg, less than 0.1% by weight of Zn, less than 0.1% by weight of Mn, less than 0.1% by weight of Sr, and less than 0.1% by weight of Cu.
 2. The heat-conductive aluminum alloy according to claim 1, wherein, based on total weight of the heat-conductive aluminum alloy, the alloying elements comprise: 8.0 to 11.0% by weight of Si, 0.4 to 0.6% by weight of Fe, 0.4 to 0.8% by weight of Mg, less than 0.01% by weight of Zn, less than 0.01% by weight of Mn, less than 0.1% by weight of Sr, and less than 0.01% by weight of Cu.
 3. The heat-conductive aluminum alloy according to claim 1, wherein the impurity elements in the heat-conductive aluminum alloy do not exceed 0.2% by weight.
 4. The heat-conductive aluminum alloy according to claim 1, wherein the heat-conductive aluminum alloy consists of 5.0 to 11.0% by weight of Si , 0.4 to 1.0% by weight of Fe, 0.2 to 1.0% by weight of Mg, less than 0.1% by weight of Zn, less than 0.1% by weight of Mn, less than 0.1% by weight of Sr, less than 0.1% by weight of Cu, not more than 0.2% by weight of impurity elements and the balance of aluminum.
 5. The heat-conductive aluminum alloy according to claim 2, wherein the heat-conductive aluminum alloy consists of 8.0 to 11.0% by weight of Si, 0.4 to 0.6% by weight of Fe, 0.4 to 0.8% by weight of Mg, less than 0.01% by weight of Zn, less than 0.01% by weight of Mn, less than 0.1% by weight of Sr, less than 0.01% by weight of Cu, not more than 0.2% by weight of impurity elements and the balance of aluminum.
 6. The heat-conductive aluminum alloy according to claim 1, wherein the heat-conductive aluminum alloy has a tensile strength of not less than 250 MPa, a yield strength of not less than 150 MPa, an elongation of not less than 3.5%, and a thermal conductivity of not less than 150 W/(m·K).
 7. The heat-conductive aluminum alloy according to claim 2, wherein the heat-conductive aluminum alloy has a tensile strength of not less than 270 MPa, a yield strength of not less than 160 MPa, an elongation of not less than 5%, and a thermal conductivity of not less than 160 W/(m·K).
 8. (canceled) 